I think a dirt cheap 50cc scoot and a cbt might be the way to go to see if she gets into it. She's quite a nervous driver, actually we don't have access to a car now we live together but when she lived at home she was so I'm not entirely convinced that two wheels of any sort will be the right way to go for her but I reckon we can do it pretty cheap as an experiment.
This might be the answer to that
http://www.uk.piaggio.com/piaggio/UK/en/news/MP3-news.html
3 wheels.
You can even get a version which qualifies as a car, so you can ride it on a full car licence.